1. Technical Field
The present invention relates to hand tools for dispensing particulate matter, for example seeds.
2. Prior Art
In my earlier British Patent Specification No. 1,578,529 there is disclosed a hand tool for dispensing seeds, comprising a V-section scoop which is vibrated mechanically or electro-mechanically to cause a batch of seeds within the scoop to be dispensed one at a time from the end of the scoop. A small barrier extends transversely across the bottom of the scoop at its discharge end portion and acts as a weir to facilitate the separation of the seeds which jump over the barrier when vibrations are applied. In practice it has been found that the barrier does operate satisfactorily provided that the scoop is held within a few degrees of a specific angle. If the scoop is held at too steep an angle there tends to be an uncontrolled flow of seeds.
In an attempt to overcome this problem a second barrier was placed upstream of the barrier at the dispensing end portion. This second barrier took the form of a transverse panel extending across the scoop with an opening provided at the apex of the barrier immediately adjacent the bottom of the scoop to define an aperture through which seeds held behind the barrier could pass singly.
This arrangement necessitated a different size of aperture for different sizes of seed and in order to enable the dispenser to handle a wide variety of seed sizes it was necessary to provide a series of interchangeable barrier panels each with a different size of aperture. Although functionally this arrangement worked satisfactorily, it did have the disadvantage that it was not always easy for the user to select the appropriate barrier and also there was the possibility that the user could mislay the barriers which were not in use.